You can’t yet see winter coming, but it’s coming anyway, and quickly. Your car should soon be receiving some attention in order to get ready: it needs winter tires in good condition, obviously; winter wiper blades to cope with snow and ice; and depending on its age, perhaps a new battery.
There is one thing that many people seem to forget, however: engine coolant.
The first thing to understand is that however cold it gets outside, the engine in your car requires coolant. On average, a piston engine runs at nearly 100oC, year-round.
At the factory, the radiator was filled with an ethylene glycol-based solution; this should generally be changed every 5 years or 250,000 kilometres. If your car is less than 5 years old, you need not worry about this vital fluid.
On the other hand, if you and Old Faithful have been together longer than that, it would be a good idea to check your radiator fluid. Its effectiveness can decrease over time, and even a microscopic leak can mean the eventual loss of a significant quantity of coolant.
Dealerships usually carry out a careful inspection before selling a used car, but If you bought one from an individual or an independent non-certified reseller, it would also be a good idea to check what is in your radiator. It just may be filled with plain water! In summer, that may not cause too many problems, as long as you do not ask too much of the engine, but when the thermometer dips below freezing, you could end up with ice cubes under your hood. Finally, remember that it is not enough to buy coolant in the pure form: it will freeze below -13oC. You should use premix, or make it yourself according to the manufacturer’s recommendations.